Bacteriophages (phages) are viruses that infect bacteria. Bacteriophage, which derive their name from the Greek word “phago” meaning “to eat” or “bacteria eaters”, were independently discovered by Twort and by D'Herelle in the first part of the twentieth century. Early enthusiasm led to their use as both prophylaxis and therapy for diseases caused by bacteria. In the U.S. during the 1940's, Eli Lilly and Company (Indianapolis, Ind.) commercially manufactured six phage products for human use including preparations targeted towards staphylococci, streptococci and other respiratory pathogens. With the advent of antibiotics, the therapeutic use of phage gradually fell out of favor in the U.S. and Western Europe and little subsequent research was conducted. However, in the 1970's and 1980's there were reports of bacteriophage therapy continuing to be utilized in Eastern Europe, most notably in Poland and the former Soviet Union. In light of recent concerns that antibiotics are losing their effectiveness through overuse, there is renewed interest to the potential of phage therapy as a weapon against bacterial infection (Carlton, 1999. Arch. Immunol. Therap. Exper. 47:267-274; see also News Focus, Science (25 Oct. 2002) vol. 298).
Pink pigmented facultative methylotrophs (PPFMs) are bacteria in the genus Methylobacterium. PPFMs are ubiquitously distributed on plant surfaces, in soil containing organic matter and in water. They are not generally thought to be pathogenic, although recent reports indicate that the PPFMs might act as opportunistic pathogens in immuno-compromised patients. Previously, it has been demonstrated that PPFMs stimulate plant growth in vivo and in vitro, they participate in plant nitrogen metabolism (Holland and Polacco 1992. Plant Physiol.98:942-948), they enhance seed germination (Holland and Polacco 1994. Ann. Rev. Plant Physiol. Plant Molec. Biol. 45:197-209), they stimulate root growth (Holland 1997. Rec. Res. Dev. Plant Phys. 1:207-213) and they manufacture cytokinins (Holland et al. 2002, In: Lindow et al. (eds.) Phyllosphere Microbiology, APS Press, St. Paul, Minn.). These findings have led to the issuance of U.S. Pat. Nos. 6,329,320; 6,174,837; 5,961,687; 5,512,069 and 5,268,171. All of these patents are herein incorporated by reference. Other applications are pending directed to: 1) the isolation of elite strains of PPFMs found to provide increased yields of, for example, methionine and vitamin B12 in plants (see for instance U.S. patent application Ser. No. 09/958,175 filed May 8, 2002), and 2) for altering the fertility of a plant (U.S. patent application Ser. No 10/296,158). The entirety of these two applications is incorporated by reference herein.
Lindner et al., in U.S. Pat. No. 6,255,467, the entirety of which is incorporated by reference herein described the isolation of a bacterium from human blood, which he designated HBB (Human Blood Bacterium). Lindner et.al. represent that the bacterium is present in everyone's blood, but that high numbers of the bacterium are associated with the symptoms of auto-immune disorders including chronic fatigue syndrome, fibromyalgia, multiple sclerosis, lupus erythematosis and rheumatoid arthritis. The subject matter of the Lindner patent includes the use of the bacterium as a basis for diagnosing auto-immune disease and treatments for these disorders based on antibiotic therapy. Based on DNA sequencing of selected portions of the human blood bacterium genome, the bacterium was identified by Lindner et al. as a close relative of Methylobacterium. 
The present inventors have identified and isolated the first known bacteriophage effective at infecting and lysing species of Methylobacterium (Methylobacterium spp.) from plant sources. In addition, it has now been found that this bacteriophage can selectively destroy the blood borne bacterium, HBB. No phages effective against Methylobacterium or HBB have been previously described in the literature.